This project involves the study of the origin and development of social motivation in the dog. Specific goals for the coming year are: A. To study the interaction of separation distress with that of fear, (this is by far the most important of such interactions from the viewpoint of the theory of attachment), B. To determine the time at which the capacity for making social attachments develops and the factors which modify it, C. To study the development of the capacity for 24-hour memory by a new experimental design in which puppies are tested for three consecutive days (7-9, 9-11, 11-13, and 13-15 days). In this way the interacting factors of experience and maturation can be studied by comparing the last day's performance of one group with the first day's performance of the next older group.